Modeling of dark current in mid-infrared quantum-well infrared photodetectors

Optimization of dark current is a key technological issue to be addressed in order to improve quantum-well infrared photodetector (QWIP) performance. We develop a model for the description of current-voltage curves in mid-infrared QWIPs, which usually span a range of electric fields in which both low-field as well as high-field carrier transport effects are visible, especially at low temperatures. The model separates the I-V curve into a low-field and a high-field region allowing us to identify and separate the effects ascribed to miniband transport and carrier localization, respectively. We then compare simulations with our measurements of the I-V curves of mid-ir QWIPs finding a good quantitative agreement between theory and experiment.